The candidate is a naturopathic physician trained in integrative medicine and epidemiology who completed an NRSA Postdoctoral Fellowship (F32) focused on clinical trials in Complementary and Alternative Medicine (CAM). The candidate's long-term career goal is to become an independent clinical investigator focusing on rigorous evaluation and integration of evidence-based CAM therapies for fibromyalgia. The research, training, and mentorship will be based at the Yale University School of Medicine, with abundant intellectual, educational, and institutional resources, and a rich scholarly environment for innovative research. The candidate will work with an enthusiastic, committed, and highly accomplished team of mentors and advisors (including some from other institutions with expertise and commitment to his research and career development), and benefits from robust institutional and departmental support to facilitate completion of this mentored career development award. Didactic training will occur throughout the period of the award, including advanced courses on clinical research methods, statistics, mixed-methods research, mind-body medicine, and neuroscience. The candidate will regularly attend (and present at) weekly research in progress conferences, seminars, and lectures focused on junior faculty at the Yale School of Medicine. Training in the Responsible Conduct of Research will continue through mentorship and continuing education by the Yale Human Research Protection Program. The focus of the research in this K23 application is a dose-finding study of a popular mind-body therapy (Mindfulness-based Stress Reduction; MBSR) for patients with fibromyalgia. It will investigate the benefit of different doses (high, standard, and low) of MBSR compared with an active control. MBSR is a standardized mind-body intervention that involves meditation, patient education, and group support. The eight-week MBSR protocol involves 2.5 hours of weekly instruction and 30-45-minutes of daily self-practice. Preliminary studies suggest benefit of MBSR for the alleviation of fibromyalgia symptoms, though no well-designed trials have assessed optimal dosing. The proposed study will begin a line of inquiry into the role of MBSR for the treatment of fibromyalgia systematically assessing dosing, feasibility, adherence, and preliminary efficacy. The aim of this study is to identify the optimal practical dose and treatment regimen of an eight-week course of MBSR in patients with fibromyalgia. This will be completed by: 1. Assessing the safety, feasibility, and adherence profile of three regimens of MBSR compared with an active control in patients with fibromyalgia. 2. Assessing the clinical benefits of three regimens of MBSR in patients with fibromyalgia measured by changes in validated outcome measures. As dosing in clinical trials of CAM interventions are often extrapolated from prevailing practice patterns (with doses based on anecdotal evidence), null results in clinical trials due to type two errors can occur. The purpose of this study is to obtain estimates of the magnitude of effect so that future trials can be designed with appropriate statistical power. The study will assess three 'doses' of a non pharmacological CAM intervention to determine an optimal practical dose of an eight-week course of MBSR in patients with fibromyalgia. This is the first formal dose-finding study on MBSR. It will utilize standard, validated measures of pain, physical function, quality of life, and mindfulness, as well as an active control intervention. It ill provide high-quality data for a larger, more definitive R01 submission. Results obtained from this initial study will be the first step in developing a graduated, stepwise CAM/integrative medicine algorithm for the treatment of fibromyalgia. The goals of this application are consistent with NCCAM's emphasis on treating chronic pain and Strategic Plan goals to support clinical evaluation and intervention studies of mind/body interventions and support high-quality research training and career development opportunities to increase the number, quality, and diversity of CAM researchers. The candidate will regularly meet with his mentor and advisory committee to ensure consistent progress and adherence to the training, research, and career development plan. This will help ensure a productive period of career development, and provide the skills, experience, and guidance in order to advance to an independent clinician-researcher focused on fibromyalgia, CAM, and integrative medicine interventions.